this sense of flow is a monstrous illusion—so says contemporary physics. And Newton was as much a victim of this illusion as the rest of us are. It was Albert Einstein who initiated the revolution in our understanding of time. In 1905, Einstein proved that time, as it had been understood by physicist and plain man alike, was a fiction. Our idea of time, Einstein realized, is abstracted from our experience with rhythmic phenomena: heartbeats, planetary rotations and revolutions, the swinging of pendulums, the ticking of clocks. Time judgments always come down to judgments of what happens at the same time—of simultaneity. … What Einstein had shown was that there is no universal “now.” Whether two events are simultaneous is relative to the observer. And once simultaneity goes by the board, the very division of moments into “past,” “present,” and “future” becomes meaningless.
Does time have a future? Yes, but how much of a future depends on what the ultimate fate of the cosmos turns out to be.
If there is one proposition about time that all scientifically inclined thinkers can agree on, it might be one due to the nonscientist Hector Berlioz, who is reputed to have quipped, “Time is a great teacher, but unfortunately it kills all its pupils.”